Starting loads for 300 RUM

Discussion in 'Reloading' started by MontanaRifleman, Sep 11, 2009.

  1. MontanaRifleman

    MontanaRifleman Well-Known Member

    Messages:
    6,068
    Joined:
    May 21, 2008
    Hey guys, I'll be doing some load developement soon for my 300 RUM Sendero. Never did this before for a 300 RUM, so I thought I would get some opinions on my start loads.

    180 E-Tip, 97.5 Retumbo
    180 E-Tip, 93.5 H1000
    200 AB, 92.5 Retumbo
    200 AB, 89 H1000
    210 Berger, 88.5 Retumbo

    COAL on the E-Tips are 3.685
    COAL on the AB's are 3.690
    COAL on the Berger's are 3.850

    Are these starting loads low enough in your opinion or are any of them too close to max?

    Thnaks,

    Mark
     
  2. bigbuck

    bigbuck Well-Known Member

    Messages:
    1,650
    Joined:
    Jun 20, 2009
    92.5 grains of retumbo is a little on the high side for my 300 rum (but) I load for the 210 berger .

    Do you measure your COAL from the tipp of the bullet to the base If so do you have an wyatt extended box mag?
     

  3. MontanaRifleman

    MontanaRifleman Well-Known Member

    Messages:
    6,068
    Joined:
    May 21, 2008
    Thanks Bigbuck,

    No Wyatt's box, I just have the factory mag and the AB's and E-Tips barely fit. The Bergers are seated to the lands and one will fit at the top of the mag. I would only use the Bergers for extreme ranges, so I figure i will have time to single feed them if I need to. Yep, I measure from tip of bullet to base.
     
  4. tobehunted

    tobehunted Well-Known Member

    Messages:
    63
    Joined:
    Jan 15, 2009
    88 gr of retumbo for the 210 berger caol 3.870 was where i started when i was working the load up for my 300 rum. I went up to 91.6 where i started to get some pressure ( the best load also ) go figure. I chronographed them at 3040 fps. I also worked up the 190 bergers with retumbo and ended up at 94.5 (excellent group ) 3100 fps . Took them both out to 400 yds for group testing and the 210 bergers shot 4 1/2 inch but the 190s shot 2 1/4 groups so i stuck with them.